1. Field of the Invention
This invention generally relates to a digital still video camera, and more particularly relates to a digital still video camera for recording image data of a subject to a recording medium, for example, a flash memory card.
2. Discussion of the Background
FIG. 3 is a block diagram of a conventional digital still video camera including a video processing unit formed by a lens 1, a CCD (Charge Coupled Device) 2, a pre-processing circuit 3, an A/D (Analog/Digital) converter 4, a memory 5, and a camera processor 6 and having video signal output 19.
The conventional camera of FIG. 3 further includes an encoder/decoder 7, a FIFO (First in First Out) circuit 8, a MCC (Memory Card Controller) 9 and a flash memory card 10. The FIFO circuit 8 is connected to MCC 9 and inputs data to and from the MCC 9. The flash memory card 10 is detachably connected to MCC 9, and memorizes recording data controlled by the MCC 9. A CPU 11 controls the camera processor 6, the encoder/decoder 7, and the MCC 9 (including FIFO circuit 8) using the bus 18.
Audio is input via a microphone 21, a first AMP (first amplifier) 12 which amplifies voice data input by the microphone, an A/D (Analog/Digital converter) 13 connected to the first AMP 12, an ADPCM (Adaptive Differential Pulse Code Modulator) 14 connected to A/D 13 and the MCC 9, a D/A (Digital/Analog) converter 15 connected to the ADPCM 14, a second AMP (second amplifier) 16 connected to the D/A 15, and output to an audio output 20 connected to second AMP 16.
A subject is image-formatted on the CCD 2 through the lens 1. The image formatted by CCD 2 is processed (for example gain control) in the pre-processing circuit 3, and converted to digital image data in the A/D converter 4. In the camera processor 6, the digital image data are processed in a matrix process and a raster block (8.times.8) process. In the encoder/decoder 7, the processed digital image data are encoded. The memory is used as an image memory in producing a brightness signal or a color signal and processing a matrix based on the digital image data input from the A/D converter 4, or is used as a memory for the raster block process in encoding or decoding. The encoded digital image data are input to the FIFO circuit 8 and recorded in the flash memory card 10 by MCC 9 as recorded image data.
A voice input signal is converted to an electrical signal by the microphone 21. In the first AMP 12, the electrical signal is amplified. In the A/D converter 13, the amplified electrical signal is converted to digital voice data, and in the ADPCM 14, converted digital voice data are encoded. The encoded digital voice data are recorded in the flash memory card 10 by MCC 9 as recorded voice data.
In case of reproducing recorded image data, the recorded image data are input to the FIFO circuit 8 by MCC 9 and decoded in the encoder/decoder 7. The decoded recorded image data are input and converted to a video signal in the camera processor 6, and output through the video signal output 19.
In case of reproducing the recorded voice data, the recorded voice data are input and decoded in the ADPCM 14. The decoded recorded voice data are input and converted to an analogue audio signal in the D/A converter 15, and output through the audio output 20.
However, in such a digital still video camera of the prior art, the flash memory card 10 has difficulty to rewrite data by 1 byte because an erasing unit of the flash memory card 10 is larger than 1 byte. The digital still video camera of prior art needs an optional memory which has larger capacity than the capacity of the erasing unit of the flash memory card 10. The necessity for the optional memory increases the size and cost of the conventional digital still video camera.